An increased consciousness towards maintaining a healthy environment necessitates a transition from volatile organic solvent based coating preparations to those of aqueous based systems. The obvious advantages of this are the alleviation of evaporation of large quantities of organic solvents into the environment and the minimization of problems associated with industrial worker exposure to organic solvents.
Since laws have been enacted (South Coast Air Quality Management District (SCAQMD) Rule 1136), this concept of minimization of volatile organic solvent use as a component, in coating preparations by using instead an aqueous based system has become of paramount importance as mandated minimization of volatile organic compounds (VOC) is realized. Another factor which makes adaptation to aqueous systems desirable is that the clean-up of water-borne systems does not require organic solvents. An economic benefit is also realized by eliminating the use of expensive organic solvents which are continually increasing in cost.
As an alternative to elimination of volatile organic solvents, U.S. Pat. No. 4,675,374, discloses the use of liquid components sufficiently low in viscosity to be mixed and applied to a surface, thus requiring no organic or aqueous carrier. This methodology may only have limited scope however, as many polymeric compositions consist of solids or highly viscous liquids which require a solvent system to allow for application.
The applicants are also aware of an increasing trend towards the use of aqueous systems as disclosed in U.S. Pat. Nos. 5,252,657; 4,814,373; 5,227,433; 5,093,405 issued to Frankel et al, U.S. Pat. Nos. 4,677,168; 5,039,759 issued to Hoy et al, U.S. Pat. No. 4,977,219 issued to Watson, Jr., U.S. Pat. No. 4,748,167 issued to Das et al.
The use of coatings is ubiquitous in man-made products and almost every man-made item has surface coating serving either a protective or a decorative role or possibly both. In the spirit of both the decorative and protective role of a coating, it is often desirable to provide a surface coat that has the appearance of a distressed, antique, or aged look, to be referred to as a crackle coat. In a direct parallel with the necessity to move from the volatile organic based solvent systems for coatings to an aqueous based system as previously discussed, coatings which provide this antique look, traditionally prepared in an organic solvent system also require changing to an aqueous based system for the previously stated reasons. While the above references give examples of aqueous based systems for coatings, thus eliminating or minimizing the volatile organic component of the systems, they do not address a decorative coating that provides the antique or crackle appearance. Further, examples of coatings which are prepared as aqueous systems, but do not include a decorative coating that provides the antique or crackle appearance are U.S. Pat. No. 4,196,107 to Jones et al, U.S. Pat. No. 4,292,220 to Novak et al and U.S. Pat. No. 4,276,329 to Vasisth et al. Therefore, there is a need for a coating and a method which is an aqueous based coating system that produces an antique or crackle appearance to the coating.